This invention relates to an arrangement to couple an auxiliary switch mechanism to an electrical switchgear unit, perferrably a contactor, with a contact sliding piece holding the movable contact pieces and a housing holding the fixed-mounted contact pieces.
In an arrangement known from U.S. Pat. No. 2,977,438, a housing of an auxiliary switch mechanism is locked in place with the housing of a switchgear unit. The contact slide piece of the auxiliary switch mechanism is brought into operative connection with the contact slide piece of the switchgear unit by a non-positive connection only. Thus, said arrangement does not ensure that both contact slide pieces necessarily assume the same position.
It is further known from U.S. Pat. No. 2,672,536 to provide the contact slide piece and housing with claw-shaped projections which can make contact by sliding sideways against each other. If in this configuration the auxiliary switch mechanism is slipped "ON" while the unit is "ON", then the contact slide pieces will not be coupled.